This invention relates to apparatus for use in the sharp dissection of tissue or bone in arthroscopic surgery and the like; and more particularly to apparatus including a rotary tool adapted to be driven by a rotary motor at speeds sufficient for sharp dissection of anatomical structures.
The invention is concerned particularly with the field of arthroscopic surgery, wherein surgical procedures are performed within the confines of an anatomical joint, for example, without widely opening up or exposing the joint. These procedures are carried out by providing one or several small openings into the anatomical joint, inserting through those openings the probe of an arthroscope which allows the surgeon to visualize the area to be operated, irrigation apparatus to flush out particles of dissected material, and surgical apparatus such as dissecting apparatus.
The arthroscopic dissecting apparatus is used to dissect and cut away soft tissue such as meniscus, synovium and cartilage found within anatomical joints. Since such surgery is frequently performed in a small confined area, the portion of the dissecting apparatus received within the area must be small; and the apparatus must have exactly engineered cutting edges to enable dissection of the desired tissue without injury to adjacent sound anatomical structures.
A principal object of this invention is to provide rotary dissecting apparatus for use in arthroscopic surgery to be driven by a rotary drive motor at elevated rotational speed.
Another object of this invention is to provide such dissecting apparatus having a rotating dissecting tip at its distal end, and having protective means to prevent inadvertent dissection of sound anatomical structures.
A further object of this invention is to provide such apparatus having a rotary dissecting tip adapted to be driven at rotational speeds of 2000 rpm or higher.
Still another object of this invention is to provide such apparatus wherein the dissecting tip is protected by shrouds adapted to guide the tip with respect to the material to be dissected.
These objects are attained in dissecting apparatus which includes broadly a rotatable dissecting tool and a guide for the dissecting tool. The dissecting tool comprises and elongated shank having an axial chuck engageable means at its proximal end and having a dissecting tip at its distal end. The chuck engageable means is adapted to be engaged and rotatably driven by the chuck of a rotary motor. The dissecting tip includes at lease one cutting surface disposed to dissect material with which it is engaged. The guide comprises an elongated hollow shank, enlarged housing means at the proximal end of the shank for attachment to the rotary motor, and protective shroud means formed at the distal end of the shank for partially enclosing the dissecting tip. The shroud means provides an open face for exposing the dissecting tip to the material to be dissected. The guide shank includes bearing means for rotationally supporting the tool shank.
These objects are attained more specifically in such apparatus wherein the guide shank has an axial passage adjacent to its distal end dimensioned slightly larger than the tool shank; and wherein the guide shank is provided with at least one transverse port opening from that passage for the egress of material brought into that passage. The tool shank has an archimedes screw formed adjacent to its distal end for coaction with that guide passage for conveying material to said egress port.